To develop safe and efficient methods for prenatal diagnosis of the hemoglobinopathies. BIBLIOGRAPHIC REFERENCES: Nathan, D.G.: Progress in the Methodology for antenatal diagnosis of the beta chain hemoglobinopathies. Trans. Assoc. Amer. Phys. 88: 168-176, 1975. Alter, B.P., Friedman, S., Hobbins, J.C., Mahoney, M.J., Sherman, A.S., McSweeney, J.F., Schwartz, E., and Nathan, D.G.: Prenatal Diagnosis of Sickle Cell Anemia and Alpha G-Philadelphia: Study of a Fetus also at risk for HB S/beta plus-Thalassemia. New England Journal of Medicine, in press, 1976.